All sperm are not equal

Feb 13, 2014

An experimental study from researchers at Uppsala University provides evidence that in Atlantic salmon, selection acting upon sperm phenotypes within a single ejaculate of a male affects the time until hatching in the resulting offspring. The results are now published in Biology Letters.

While competition between sperm of different males is recognised as a major form of , selection of sperm within an ejaculate is considered to be without consequence based on the long standing assumption that sperm phenotype is unrelated to its haploid genetic content, i.e., "one can't judge a book by its cover."

"Contrary to the general assumption we have seen that selection during the gametic stage can be of importance in animals," says Simone Immler at the Department of Evolutionary Biology, Uppsala University.  

The importance of variation in within an ejaculate for the quality of the resulting offspring is much debated, particularly in the context of artificial insemination and fertilisation methods. Because artificial fertilization sidesteps many of the selective mechanisms occurring under natural circumstances it may affect offspring fitness.

Explore further: Purring tempo, sliding notes grab cats' attention

More information: Immler S, Hotzy C, Alavioon G, Petersson E, Arnqvist G. 2014 Sperm variation within a single ejaculate affects offspring development in Atlantic salmon. Biol. Lett. 20131040. dx.doi.org/10.1098/rsbl.2013.1040

add to favorites email to friend print save as pdf

Related Stories

Big sperm don't always win the race

Jan 31, 2014

When females mate with more than one male, each one's sperm has to compete to get to her eggs. Until now, researchers had thought the fastest sperm would dominate.

Females fight back in sperm wars

Oct 17, 2013

(Phys.org) —Females exposed to a risk of sperm competition have been found to produce more defensive ova compared to the eggs of females reared under no risk of sperm competition, according to researchers ...

Study of salmon sperm success shows need for speed

Oct 30, 2013

(Phys.org) —When salmon spawn, males competing to fertilise eggs will win or lose based primarily on their sperm swimming speed, according to a collaborative study by researchers from the University of ...

Sexual selection in the sea

Jun 04, 2013

Biologists have uncovered new insights into how the male sexual behaviour of the peculiar southern bottletail squid is primed to produce the greatest number of offspring.

Recommended for you

How animals survive Norwegian winter nights

29 minutes ago

Norwegian mammals and birds have many different methods of surviving long, intense winter nights. A biologist from the Norwegian University of Science and Technology (NTNU) University Museum reveals their ...

A molecular compass for bird navigation

Feb 27, 2015

Each year, the Arctic Tern travels over 40,000 miles, migrating nearly from pole to pole and back again. Other birds make similar (though shorter) journeys in search of warmer climes. How do these birds manage ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.